Existing securities order processing and routing systems may make routing decisions based on current order book conditions at various potential order destinations such as securities exchanges, market makers or specialists, and/or ECNs (Electronic Communication Networks). ECNs are private electronic networks that allow for placement of securities trading orders and are fully automated to match orders and set prices for trades without the intervention of market makers. Order routing decisions, whether to securities markets, market makers or ECNs, may also be based at least in part on historical data that has been compiled for the order destinations. However, routing decisions based only on current order book conditions and/or on historical data that has customarily been used may not optimize trading performance.